Pressure-filter.



No. 859,749. PATBNTED JULY 9, 1907.

A. E. DAVIS. PRESSURE FILTER.

Arrmourox num JUNE 2v. 1905.

' s sums-sum 1.

Y PATBNTED JULY 9', r1907. A. E. DAVIS.

PRESSUREy FILTER. .APPLICATION FILED JUNE 27. 1905.

' a SHEETS-SHEET 2.

PATENTED JULY 9, 1907- l A. E. DAVIS.

PRESSURE FILTER. PPLIoATroN FILED JUNE 27, 190s PATENTED JULY 9, 1907. A. E. DAVIS. PRESSURE FILTER.

APPLIOATION FILED JUNI: 275. 1905.

SHEETS-SHEET s.

z lll No. 859,149. EATENTEE JULY 9, 1'907. A. E. DAVIS. PRESSURE FILTER.

' APPLICATION FILED JUNE 27. 1905.

8 SHEETS-SHEET 6.

A. E. DAVIS. .l PRESSURE FILTER.

PATBNTED JULY 9, 1907.

APPLICATION FILED JUNE 27, 1905.

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N I Q 8 SHEETS-*SHEET 7.

B SHEETS-SHEET 8.

'PATENTED JULY 9. 1.907.

A. E. DAVIS.` PRESSURE FILTER. -APPLIOATION FILED .TUNE 27. 1905.

PATENT oEEIoE.

ALFRED EDWIN Davis, oF JoHANNEsBURG, TnANsvAAL.

PRESSURE-FILTER.

l Specification of Letters Patent.

`Parental .my 9,1907.

Application filed June 27,190.5. Serial No. 267,182.

To all 'whom it may concern:

Be it known that I. Ani-RED EDWIN DAVIS, a subject of the King of Great Britain, residing at Johannesburg, in the Colpny of the Transvaal. have invented certain new andfuseful improvements in Pressure-Filters, of which the following is a specification.

This invention has reference to pressure `filters or apparatus employed in the processfof treating auriferous or other metalliferous ores` forthe recovery of the preciousor other metals for filtering or separating the liquids from the solids such as slimes andthe like.

rThe invention has particular reference to that form of pressure filter in which a series or'number of vertically disposed filter plates are arranged inside a receptacle into which the slimes or other material to be filtered, is passed the separation or filtration of the solid matter being effected by the deposition of the particles-of solid matter-on the superfices of cloth or other filtering mediaY covering the surfaces of said plates, the separated `liquid flowing along grooves or flutes in the surfaces of the platesv to a common outlet or delivery.

As heretofore constructed considerable difficulty has been experienced in discharging the pressure filters, that is to say it has lieenfoulnd diflicult if. not impossible to detach the deposited solid` matter or cakes of slime which form on the outer surfaces of the filtering media owing to the adhesion of the solid matter to the edges of the plates and the adjacent surfaces vof the receptacle in. which said plates are arranged.

The displacement of the solid matter from the surface of the filtering' media has been effected by causing a flow of liquid between Ythe plates and said filtering media and the depo'sited matter or cake of slime formed thereon, in the reverse direction to that in which the apparatus 'operates in the process of filtration or separation of the liquids (cyanid or other solvent solutions of the gold or other metal, wash waters or the like) but .owing to the adhesion of the solid matter or cake of slime to certain portions oftheplates and top and sides of the receptacle in which said plates are arranged, said solid matter has not been easily detached and its removal in the manner proposed has not been practicable.

The invention relates. alsov to the construction of the receptacle in which the filter-plates are arranged, to facilitate the discharge of the separated solid matter and to allow of said discharging being effected without necessitating the'removal lof `the filter plates or dis- `lili .turbing the flterngllmaterial surrounding Asalidrfplates so that all that is necessary in the operation of dis-1 i 'l The linvention `further'relates to the method of con struction of the filter plates and to the means for attaching or securing thereto the filtering media so that the operation of attaching the same and arranging same inside the receptacle is performed more eXpwlitiously than with the present arrangements.

My invention further contemplatesother structural alterations in the details of the machine as will he .hereinafter more particularly described.

In order to facilitate the description of thc present 'invention I append drawings illustrative thereof which are marked with letters of reference corresponding to the following description.

In the drawings: Figure l represents a view of the complete filter showing the l:filter plates in vertical transverse section. Fig. 2 is a view of the complete filter showing the receptacle in section and one of thc plates in side elevation with the filtering media removed, or representing a section on line -x Fig. l. Fig. 3 represents a side elevationoi` a slightly modified form of filter plate with'the filtering media removed. Fig. Ll is ahorizontal section taken through a portion of one of they filter4 plates as at present constructed showing the manner in which the solid matter or cake of slime is deposited on the surface of the filtering media and how it adheres to the sides and iop of the receptacle. Fig-4f* is a horizontal section on line xlx of onol sideof thel filter plaie shown in Fig.

2. Fig. 5 shows a horizontal section of 21- portion of one ofthe filter plates with my improvement applied thereto for preventing -thc solid matter being deposited on the sides of the receptacle. Fig. 6 shows n. vertical section of ii. portion of'one of the filter plates with my improvement applied thereto for preventing the deposition of the solid mutter on thc top or cover' ter-plate to the upper portion and also one arl'angcmentfor fixing the filtering media over the sui-face of said plate. Fig. 10 is a transverse section on line z-z Fig. 9. Fig. 11 is a side elevation illustrativo olla slightly modifiedarrangement for securing the lower portion of the filter plate to the upper portion. Fig. 12 is a transverse sectionon lineI Fig; ll. Fig. ].3is a side elevation showing a further modification of the arrangement forsecuring the lower poi-lion of .the filter plateto the upper portion. Fig. 14 a transsection on line :iz-z Fig. 13. I-I`ig.- 15 is a side elevation-of a portion of one of -the filter plateswith part of the filtering media removed showing a further means for fixing the lower portion to. the upper portion y of the filter plate. Fig.' -16 is a planV ofthe lower pa n tion of the plate shown in Fig. 15. Fig. 17 is a transverse section on line y-z Fig. 5, and Fig. 18 is a frontl .more particularly in Figs. 1 and 2 of the drawings. it-

comprises the filter proper or the receptachl l consisting ofthe four side plates 2 and the top and bottom plates 3 and 4. The top plate or cover 3 may be bolted or otherwise secured to the sides 2 of the filter' l.

'lhe bottom plate or door 4is hinged along one odge 4a (see Fig. 2) to one side of the receptacle or filter l and it is maintained in its closed position by means ofvtwo or more 'swing bolts 5 which at their upper ends are free to move on pins 6 fitted between the strengthening ribs or webs 7 formed on the outside of theA side'plates 2.- The bottom 4 is constructed with open ended slots 8 in whichthe supporting swing bolts 5 are located when the filter is closed. 0n the ends of the. bolts 5 beneath the slots 8Aar'e arranged a washer Y 25 fland nut', y10, which serve for closing the bottom 4 against the lower edges of the sides 2. The bottom 4 is also constructed with the strengthening ribs or webs l1 similar to the side plates 2.

In the top plate or cover 3 of the filter 1 are formed a number ofparallel slots 12 which serve for supporting the filter plates inside the receptacle l. The filter plates 13 are as seen in Fig. 1, constructed with longitudinal projections or ribs 14 forming shoulders in their' upper portions which rest along the edges of the slots 12 in the top plate 3. The filter plates 13 are secured to the top plate 3 b y means of bolts 15 which passthrough the upper portions, at or in proximity to either end as seen in Fig. 2.

The filter plates 13 (see Fig; 2) are constructed on both sides with parallel and vertical grooves 16. In the top of the plate 13 holes 17 are formed at suitable distances apart which holes 17 communicate with verticalports 18 in vcommunication with the main port 19 formed in the upper portion of the filter plates 13. The holes 17 are placed in communication with lthe Whole series of grooves 16 by means of the inclined y round the edges ofthe plates 13, and in any desired i Vdeposition of the solidmatteron. any portion of the intermediate position, and fixed to the platesby means' of screws or the-like 23, as shown in Fig. 2.

With'the object of preventing the settlement or liltergplate i3 adjacent to the sides or top of the filter,

'the sides or top oi' the filter plates may be made with' a nou-filtering strip or ungrooved portion 26. In Fig.

4 a horizontal section of a portion of a filter plate.

13 as at presentconstmcted is shown. ln this case the grooves 16 along which the separated liquid fiows to the exterior of the filter, are formed over practically the entirev surface of the plate 13. At one edge 24 of the plate 13 I illustrate the fonr more or less that the deposited matter' or cake of slime or other solid matter' 25 assumes in the working of the press. In Fig. 4 it will be noticed that tlresolidmattcr is deposited and accumulates on the fixing strips 22 over the filtering media 21 and round the edge of the plate 13. When the edges of the plates 13 are adjacent'to the sides 2 or top 3 of the press 1 the solid matter is deposited'on the sides and top of the filter asis indicated at 24 in Fig. 4, the adhesion of which solid matter, as pr'eviously explained, impedes the discharging of the filter' 1 and interferes with itsproper working.

In Fig. 2 the filter' plates 13 are shown constructed with the non-filtering strip 26 along the top or adjacent to the cover or top plate`3.' In this case the vertical edges or sides of the plate 13 are removed sufficiently far fromA the sides 2 of the press toprevent theysolid matter being deposited thereupon in the working of the apparatus, as seen more particularly in Fig'. 4?. i

In Fig. 6 I illustrate the non-filtering strip 26Aformed section of one side of the plate13 showing the non-f filtering strip 26 beyond the grooves or corrugations 16. ln Fig. 3 the plate 13 is (as in 2) formed with the vertical grooves or corrugations 16 and with the inclined grooves 20 at the top placing the vertical grooves 16 in communication with the holes 17,v the latter communicating with the ports 18 leading to the main port I9 in the upper portion of the plate 13. 15a are the bolt holes for fixing Athe plate 13 to the top or cover 3. It will be noticed that the non-filtering strip 26 is in each case also covered by the filtering media 21 and that the fixing strips or laths 22 are arranged along the outer edge of said non-filtering strip or strips 26.

The filterplates 13 as shown at-27 in Figs.` 1 arid6 A i are preferably formed with grooves for thereception of the fixing stripsr 22 in order ythe more efectuallyto prevent the passage of any of the4 solid matterbetween the filteringmedia 21 and 4the plate 13. Th'e main ports- 19 in the; upper. portions of. the several filter plates 13 are placedv in communication with the outflow or delivery pipe. 28-for the separated wateri or other liquid, by means of small branch pipes 29` (see Fig. 2). The delivery pipe` 28 is in Fig. 1 shown fitted with a' blank flange or cover 3Q at one end. .The de livery pipe 28 between the filter 1 and `thepoint of discharge is fitted'with a valvey 31 for regulating ory controlling'the outflow. For the purpose of obtaining' the reverse fiow I provide a tank or other receptacle 32 for wateror other fluid which may be either in a gaseous .or liquid form, which tank 32 is placed 'in communication with the delivery pipe 28 by means of 32 to the delivery pipe 28, branch pipes 29, main portsA 19, ports or passages 18, and between the grooves or corrugations'l in the filte1` plates 13 and the filtering media 21,

At or in proximity .t-o the filter 1 is arranged the inlet or admission pipe 35, through or along which the slimes or mixture of liquids and solids fiows to the interior of the filter 1. This admission pipe 35 is placed in communication with the interior of the filter 1 by means of thesmall branch pipes 36 (see Fig. 2) which pipes 36 pass through the side and preferably communicate with the interior of the filter 1, midway between the filter plates 13 at the bottom so as to obtain a better distribution of the mixture inside the filter 1. 'lhe admission pipe 35 is fitted at either end with avalve 36?, 37, the one 36L for regulating or controlling the admissionA of the mixture of liquids and' solids and the other 37 for admitting water or other liquid for a purpose to be. hereinafter more fully explained. A draining pipe 38 which communicates with the admission pipe 35 between the filter l and the valve 36a is provided for draining off any of the liquid or mixture that may be contained in the filter before 'the separated solid matter is discharged. This v draining pipe 38 is also fitted with a valve 39 for closing it tothe interior of thefilter 1. j

ln Figs. 7 and 8 illustrating amodified construction of the filterl plate and an alternative means for fixing the illustrated in these figures the plate 13 is made in the form of a number of vertical sections 40 joined at the top by the non-filtering 'strip 26, and in its upper portion above the non-filtering strip 26 it is formed at either side with a horizontal groove 27.. Through the y plate 13 be'een the grooves 27 are formed a number of holes 42'. The filter cloth 21 or other filtering media is drawn up over the severalsections 40 of the plate 13 having been previously laced or se'wed along `the outside and bottom edges and also up b'etween the several sections or parts 40 of the plate 13 as is clearly indi'- cated at 43 in Fig. 8. It is then secured at the top by Alacing it'Y through the holes 42- and flexible fixing strip 22 as shown more particularlyin Figl. 14. yInstead of ,lacing the cloth 21 at the top `it maybe secured by means of the fixing'` strip explained.

rln Figs. 9 and 10 illustratingone modification of the 22 in the/manner previously construction Vof the filter plate 13 adaptedto simplifyy the manufacture of the same, the plate 13 is constructed in sections 40. the, upper part l'4l/being vconstructed with the shoulders 14 for resting on the topof the cover T3 at either side of the slots 12, vand with the' main port 19 and port or passage 1,8. vA portion 13 ofthe plate is not grooved while the filtering media 21 covers it fora.

strips located in the grooves 27 for securing the filtering media 2l to the plate 13. The upper portion 41 of the plate along its bottom edge is formed with recesses 44. The other and lower part 40 vof the plate (which may form the whole or one section oi the grooved portion of the plate) which is formed with the filtering grooves 1G and with the' holes 17 through which the separated liquid passes from the filtering grooves' 16 to the main port 19, is constructedwith lugs 45 which fit into the recesses 44 formed in the underside of the top portion 41.- of the plate 13, which lugs 45 are secured therein by means of pins, bolts or the like passed through holes 46 formed in the top portion of the plate and through the lugs 45,- thus attaching the two parts of the plate.` The hole 17 to which the filtered liquid passes from the grooves 16, is placed in communication with the port or passage 19 by means of the'hole or port 18 formed in the top of the part 41. l l

In the modification illustrated in Figs. 11 and l2, the filter platel3 is constructed in sections 40, similar to the last described construction. instead of forming the lugs 45 on the lower portion 40', the lower portion is attached to the upper portion 41 by means of flat tongues 47 which fit into recesses 44 formed in the under side of the top portion and in the top edge of the lower portion 40 as shown, the sections 40 forming the lower portion of the plate being connected to the upper portion 41 by means of pins, bolts or their equivalent passed through the holes 46 in the upper and lower portions of the plate, which pinsor bolts pass through coincident holes in the tongues 47. 1n the construction shown in Fig. 11`the hole 17 to which the separated liquid passes from the grooves 16 is fitted with a plug 48 formed with grooves 49 at the top and bottom, said grooves 49 being-placed in communication by means of, the vertical hole 50.

v In the further modification shown in Figs. 13 and 14,

the top portion 41 of the plate is again made separate `*from the several sections 40 forming the lower or grooved portion of the plate. It 'is also provided 4with the main port 19 and the port or passage 18 communicating with the hole 17 and with the grooves 27 formedwith the holes 42 for lacing or otherwise securing the preferably fiexible retaining strips 22 for fixing the filtering media 2l. In this construction the top portion 4l is formed with projections or lugs 45 whileftlie lower portion 40 forming one seetioneof the grooved portion of the plate is formed with a recess 44 or two side projections 51, 52, between which the lug 45 on the upper portion 41 of 'the plate 13 fits, the 1 section 40 of the plate being hinged to the upper portion 4l by 'means of a pin or v bolt passed through holes 51 in the projections or lugs 5]-,

52, on *the upper portion of the grooved section 40 and the projection 45 on the upjl'e pitiori of th plate. This construction insures that the hangin'a truly vertical plaii'; j

Inthe construction illustrated inFigspl, 16, Vand 17 which is also designed for use when the grooved or filtering portion of the plate 13 is made in sections 40, the. top portion 41 is made separate from 'the Vbottom plates will always portion or portions 4() and fixed thereto by means ofthe bolts 53'which pass vertically through the top portion i when the bolt 53 is screwed up,` and packing rings are tions or sections 40. as shown at 54. A nut 55 screwed on thc outer extremity of the bolt 53 abovethe top portion 4] of the plate i3 serves for connecting the section 40 to the iop vportion 41. One or more bolts may be used for cach section 40 of the plate 13. As shown the sections 40 are constructed with the non-filtering strips 26 across the top, and the grooved portion 40 as also the non-filtering portion, isr also covered by the filtering media 21, which may be sewed or otherwise secured thereon. As shownin the plan view Fig. 16,'he sections 40 are constructed with the grooves 16, at the ends. The hole 17 in the grooved portion of the plate 13. which is placed in communication with the grooves 1G by .the angular grooves 20 as previously described, is placed in communication with the port 19 in the upper portion 41 of the plate 13 by/means of the port or passage 18. in asimilar manner to that previously de A tho plate 40 fits closely into the outer end of thehole 18 in the top part 4l of the plate.' A piece of insertion 57 of any This nipple 56 projects for a suitable dis- I suitable material is placed between thctop of the part40 and the bottom of the part 41, to makea tight joint placed round the projecting nipple 56 and the bolt 53, for the same purpose. By this construction any section 40 of the ltering plate 13 can be easily removed and replaced ror renewed Without necessitating the re-fmoval of the Whole of thev plate..

I In Fig. 18 illustrating a slight modification of the arrangement shown'in Figs. 15 to'17, the bolt 53'which serves for fixing the sections or parts of the plate 13 to the top part 41, is located in the port or hole 18 which places the hole l7 in the top of the plates 40 yin communication with` the main port 19v in the top portion-'41. 'In this construction the hole 18 is made of larger diameter. The bolt 53 projects down the. hole 18 and is screwed into the part 40 of the plate in the bottom of the hole 17 as shown. It projects up through the top part 41and may be secured by means of the nut 55 as v In the operation of thefapparatus -the and 39 vare closed to'the-,filter'1y and'vthevalvesland 4 36 opened the lteras shown in14`igs. 1 and 2.l The slimesormixture of solids and liquids is'then pumped or otherwise forcedrunder pressure along pipe 35-andl branch pipesS into the filter 1. The liquid 4portion of themixture then passes fthrough the intersticesof the filtering media 21 and along the grooves 16 and4 inclined grooves 20 to the hole l7A and from the latter along the port 18 to the main port ,19,thy1nce through .branch pipes tojthe delivery pipe 28 and v,through the valve 31. This is continued until thecakes of charged, a quantity o f theV mixture of slime and water i or other mixture of solids and liquids will be contained in the space in .the filter adjacent to the top 3 and sides 2, not occupied by the cakes of slime or deposited solid matter. u After closing the valve 36aon the inlet pipe 35 and opening the valve39 on the drain pipe 38 -the slime and. Water or solution or mixture of solids and liquids contained in the space aforementioned., is

drained off bythe pipe 38, `andthe valve 39 then closed. I i desired'clean Watere or a weak cyanid or other solvent solution maybe passed through the filter for displacing any solution Vthat may remain or be contained in the cakes of slime deposited .on the surfaces of the filter plates 13. lnvthis event the mixture remaining in the box when the valve 36 is closed to shut off the supply need not beifirst `drained off. For this purpose the valve 37 on the opposite end oi the inlet pipe is provided. This valve 37 is then opened, the valve'31 on the delivery pipe 28 stillremaining open,.and the clean water `or weak solution fis, then .pumpedor otherwise forced through the valve `37, inletlpipe35 and. branch pipes 36into the filter and through the cakes of slime and grooves 16, 20, hole 17 ,and ports 18,l 19, and pipes ..29 to the delivery pipe,y 28 and .through the Valve 31- When thisoperation has been performed forasufiicient length of time to displace or wash out the solvent solution in the cakes, the valve 37V is closed.- The valve 39 is then opened to draw off the' Wash, water or vweak l solution remaining in the `space at the top.3 andsides 2 o the filter.' 1, andthe valve 39 thereupon closed. lt will be evident that instead of having only the-one valve 37 several such valves may be provided and ar ranged so that each admits a solution of different strength, or several Wash Waters'if .such be found neces- -sary"for`the complete treatment of the slime o r other material.` In sucha case the several valves may .be

attachedto the filter in afsimilar manner to that described in connection with the valve 37. After draining awaythe water washV tromv the filter, the -nutslO on the bolts 5, areploosened and the boltsv,swungoutv of the'slots 8inthe bottom 4, thereby-allowing the, bottom f1 to swing on the hinged edge 4". The valve 31 on the delivery pipe 28 having been ,closod'and thc valve B Iionthe pipe 33l communicating with the tank `32 opened allows the Water from the tank .32.tosfl'ow throughjth'e filter lnvtlie;` reverse direction to `that of the,filteijingownonalong thc pipe 28, ihroughuthe branch,p ipes29, ports 19, 18 and holes `17 to the grooves' .between ille solid matter or cake ofsliuieand fthefli er-v ng media 2l, whereupon thrI cakes of slinux o! .-lid matter fall out of thc box l. This is tho complete cycle of operations ande-it is rcpeatcdgeach tiunl the filtcr is filled 'and discharged.

What ,[claimuasmy invention and desire to` protect Alby Letters Patent isz- 1. In apparatus ofthe nature indicated, the combi nation of the filter or receptacleconstructedwith a bottom door, a plurality of filter plates suspended in said receptacle, each of said iilter plates communicating with a commondischarge or outlet pipe for tbe'filtered liquid, a

the top of said receptacle, each of said filter plates communicating with a common discharge or outlet pipe for the filtered liquid, an inlet pipe for introducing into the receptacle the .mixture tol be separated, a valve on said inlet pipe for shutting oi the supply fud a'nother valve for opening said pipe to a source of :supply of water or solution for washing -the strong solution out of the cakes of solid matter deposited on the filter plates, substantially as described.

3. In apparatus of the nature indicated,y in combination the flltei or receptacle tted'wlth a hinged bottom discharge door, a 'plurality of grooved platescovered with altering' material said plates being constructed with ports or passages placing them in communication with a. common outlet pipe for the separated liquid, a valve on y said outlet pipe a branch pipe communicating with said outlet pipe between the filter and valve, a valve fitted in saidpipe through which a quantity of a iiuld can be admitted to the filter in the reverse .direction to that of the filtering flow for removing the solid matter from the surince,of the flteringmaterial, a feed pipe for introducing the mixture intothe receptacle, and branch pipes between said feed pipe and the receptacle communicating with the latter at the bottom between the filter plates, a valve ou said feed pipe for shutting oillthe4 supply, a drain pipe communicatingr with the feed pipe between the filter and valve, said drain pipe being fitted with a valve for drawing'off any of the mixture that remains in the filter/after the supply valve ls closed and another val've fitted on the feedl pipe for admitting a water wash or solution to pass through the cakes of the solid matter on?v y' the surfaces of the filtering material to wash out the strong solution, substantially as described.

4. In apparatusvr of the nature indicated a filter plate provided with a plain or non-filtering strip across the top for preventing the solid matter deposited on the filtering material adhering to the top of.' the receptacle substntially as described.

5. In apparatus" of the nature indicated a'receptacle, a

, filter plate constructed with a non filtering strip 'at the top said plate rheingarrauged inside the receptacle4 so that a space is left between the sides of the receptacle ,and the'edges of the filter plate to prevent the deposition -of the solidF matter onthe top and sides of said receptacle,

substantially as described.

6. In apparatus of the nature indicated, aireceptacle, ar filter lplate Aconstructed with anon-filtering strip across thevtop and along the sides or vertical edges of the plate, to prevent deposition of solid matter on the top and sides `of said receptacle, substantially as described.

grooves nml extendingr overl the plain-or ungrooved pordescribed.,

i).g In apparatus ofthe natureindicated, the combina- 'tion' 'with the'iilter or receptacleprovided with a `bottom discharge door, of a plurality of filter plates suspended from the top lolmsaid receptacle in suchmanner that the discharfgginfrllof` said receptacle may be effected through` the bottom witl ut necessitatingy .the removal of the vfilter plates. said filter plates being so construct-ed that the solid matter deposited on their surfaces is prevented fromadhering to the inside of the receptacle around said plates, substantially as described.

10. In apparatus of .thenature indicated, the combina tion with the receptacle `itted with the bottom discharge door', filter plates arranged and secured in said receptacle in such a manner that the discharging of said receptacle can be effected through the bottom without necessitating the removal 'of the filter plates, said filter plates being so constructed that the solid matter deposited on their' surfaces is prevented from adhering tothe inside of the receptacle around said plates, and means for passing through the filtering media a duid in the reverse direction to that of the filtering flow, substantially as and for the purposes described.

11.v In apparatus of the nature indicated, the combination with the receptacle fitted with the bottom discharge door of a plurality of filter plates constructed and ai'- ranged in said receptacle@ in such a manner that the discharge muy be effected without necessitating the removal of said filter plates, said 'filter plates being so constructed and arranged that the solid mattei-.deposited on their surfaces is lprevented from adhering to the inside of the receptacle around the edges of the plates, means for draining off any of the mixture remaining in the press after the cakes are formed, means for passing through the filtering media and cakes of solid matter deposited thereon, a water Wash or weak solution, and menns'ifor passing through the filtering media a fluid in the reverse direction to that of the filtering f'low to detach the solid matter, substantially as described.

12. In apparatus of .the nature indicated, a filter plate constructed with filtering grooves and av plain or ungrooved` portion across the top and along the sides of said plate, grooves or recesses formed in the plate beyond the plain or ungrooved-portion and fixing strips `for securing the filtering material over the grooved and ungrooved portions ot said plates, substantially as described.

'13. In apparatus of the nature. indicated, a filter plate constructed` of a number of vertical A grooved sections joined across the top by a plain or ungrooved portion, a covering of,iiltering material covering the several sections of the filter plate and joined at the sides, between the sections' :in along the bottom, grooves in 'the sides of the plate ab ve the plain non-filtering strip and, fixing strips 'in said grooves for securing the filtering material on the surfaces ofthe several sections of the plate, substantially asI described,

14. In apparatus of the nature indicated, a filter plate constructed of a' number ot vertical grooved sections' joined across the top -by a plaln'or ungrooved part, a covering of filtering material for the several sections of the plate said material being joined 'at the sides, between the sections and alo'ng the bottom, grooves in the sides of the plate above the nonltering strips, holes through the plate placing the grobves in communication, flexible fixing strips in' said grooves and means threaded through the 'holesfin the grooves 'for fixing .the stripsvand filtering na terlal to the top of the plate, substantially as described.

15.` In apparatus of the nature indicated, a filter plate having filtering grooves thereinand comprising an upper-l portion and a lower portion, said parts being connected by meanso! bolts screwed into the 'lower portion and pro- `jecting through a hole in the upperportion, the upper prscrewed into said port in the one part and projecting into the coincidentA port in the other part, and packing located in the junction between` the two parts ot theYpla-te` for forming a tight joint round the bolt and nipple, substantially us tiesc'rlvb'edjl"` f -1 v 16. In appax'nt'us' of the nature indicated'a filter plate having :filtering grooves therein and comprising an upper and lower portion," the'upper portion formed with 'a main outlet port andthe lower portion with a hole in communi` cation with Ithe filtering grooves-'anditl-1e two parts with coincident `ports placing the hole inthe lower portion in communication with the main port in the upper portion', a bolt passing through the upper portion down the coincident port nd screwed into the lower' portion at the bottom of the h ole an` annular space ron-nd the bolt placing` the vhole in communication with'lthe' main portx and a nipple screwed into theport in the cnet-part and projecting into the coincident port in .the other-:spart n 'nrlpgicking l round said nipple between theu'pperandlowerl partezot the plate, subetuntially as described. l

In witness whereof I vhave hereuntofset my haudin then presence of. twojsubscrbng witn'esseu. ,4

l ALFRED` LWitnesses :I

CHAs.'OvnN`DALn, t 4

RAP.' OvENnALn.

EDWIN puis;v 

